Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
hang doi » hang di, hang loi, huong doi
ky sang » ky dang, ky tang, duy sang
nam tuc » nam thuc, nam truc, nam thuoc
va hang » van hang, va nang, va lang
doi cua » dai cua, hoi cua
cua tre » cua te, cuu tre, cua triet
nam tu » nam thu, nam thuc

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ((ky sang) OR (ky nang)) ma hoa. hieu van ((nam tuc) or (nam tu)) va hang doi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((ky sang) OR (ky nang)) ma hoa. hieu van ((nam tuc) OR (nam tu)) va hang doi cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((ky sang) OR (ky nang)) ma hoa. hieu van ((nam tuc) or (nam tu)) va hang doi cua tre*".